I have the same issue and it is really annoying. I have Ubuntu 6.10, an ATI Radeon 8500 with Mesa 6.5.1 drivers. I have not been able to reproduce the problem with Xine (after the volume control goes away there is a black box, but it almost instantly disappears).
-- Black box after changing volume when playing video fullscreen https://launchpad.net/bugs/75600 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs